TY - JOUR
T1 - Niche Packing and Local Coexistence in a Megadiverse Guild of Frugivorous Birds Are Mediated by Fruit Dependence and Shifts in Interaction Frequencies
AU - Dehling, D. Matthias
AU - Riva, Giulio Valentino Dalla
AU - Hutchinson, Matthew C.
AU - Stouffer, Daniel B.
N1 - Funding Information:
We thank Ana Paula A. Assis, Paulo R. Guimaraes Jr., Daniel I. Bolnick, and two anonymous reviewers for their constructive comments that improved the manuscript. D.M.D. was supported by a grant from the German Research Foundation (DFG 2754/1-1). D.M.D. also acknowledges funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (grant 787638) and the Swiss National Science Foundation (grant 173342), both awarded to C. H. Graham. M.C.H. acknowledges the support of a University of Canterbury Summer Scholarship and the William Georgetti Fellowship from Scholarships New Zealand. D.B.S. acknowledges the support of a Rutherford Discovery Fellowship and the Marsden Fund Council from New Zealand government funding, both of which are managed by the Royal Society of New Zealand Te Apārangi (RDF-13-UOC-003 and 16-UOC-008).
Publisher Copyright:
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PY - 2022/6
Y1 - 2022/6
N2 - Niche packing is one of the prevailing mechanisms underlying the increase in the number of co-occurring species and the extraordinary diversity of tropical ecosystems. However, it is not yet understood whether niche packing is facilitated by higher specialization and reduced niche overlap or, rather, by diffuse competition and increased niche overlap. We combined highly resolved bird-plant interaction networks, bird phylogenies, and plant functional traits to compare dietary niche overlap and foraging frequencies among frugivorous birds at seven sites in the tropical Andes. We quantified niche overlap on the basis of the traits of the plants used by each bird and related it to the degree of niche packing at the different sites. Niche complementarity decreased with increasing niche packing, suggesting that increasingly dense niche packing is facilitated by increased niche overlap. Pairwise niche overlap was mediated by shifts in foraging frequencies away from shared resources, and it decreased with decreasing phylogenetic relatedness and increasing dependence on fruit as resource. Our findings suggest that foraging choices are a key axis of diversification in frugivorous birds and that differences in resource use frequencies are already sufficient to reduce potential competition between ecologically similar species and facilitate niche packing, especially if species differ in their dependence on particular resources.
AB - Niche packing is one of the prevailing mechanisms underlying the increase in the number of co-occurring species and the extraordinary diversity of tropical ecosystems. However, it is not yet understood whether niche packing is facilitated by higher specialization and reduced niche overlap or, rather, by diffuse competition and increased niche overlap. We combined highly resolved bird-plant interaction networks, bird phylogenies, and plant functional traits to compare dietary niche overlap and foraging frequencies among frugivorous birds at seven sites in the tropical Andes. We quantified niche overlap on the basis of the traits of the plants used by each bird and related it to the degree of niche packing at the different sites. Niche complementarity decreased with increasing niche packing, suggesting that increasingly dense niche packing is facilitated by increased niche overlap. Pairwise niche overlap was mediated by shifts in foraging frequencies away from shared resources, and it decreased with decreasing phylogenetic relatedness and increasing dependence on fruit as resource. Our findings suggest that foraging choices are a key axis of diversification in frugivorous birds and that differences in resource use frequencies are already sufficient to reduce potential competition between ecologically similar species and facilitate niche packing, especially if species differ in their dependence on particular resources.
KW - Eltonian foraging niche
KW - Interspecific competition
KW - Mutualism
KW - Niche evolution
KW - Niche overlap
KW - Seed dispersal interaction networks
UR - http://www.scopus.com/inward/record.url?scp=85128782125&partnerID=8YFLogxK
U2 - 10.1086/718684
DO - 10.1086/718684
M3 - Article
C2 - 35580221
AN - SCOPUS:85128782125
SN - 0003-0147
VL - 199
SP - 855
EP - 868
JO - The American Naturalist
JF - The American Naturalist
IS - 6
ER -